Germany's Jewish community on Monday warned of an "alarming" rise in anti-Semitic violence by Arab and Turkish immigrants after Berlin police reported two unrelated attacks against Jews at the weekend.

"There's an urgent need to fight the roots of anti-Semitism, especially coming from young Turks and Arabs, and to effectively counter it," the Jewish Community in Berlin said in a statement.

"That the violence from the immigrant community is being increasingly aimed at Jews or people they assume are Jews is alarming," it added. A sensitive issue in Germany because of its Nazi past, even relatively minor reports of anti-Semitic violence make the news.

Police reported at the weekend that two women and a man were beaten, struck on the head with beer bottles and insulted by a gang of immigrants in an underground station.

Local media reports said the three were first asked if they were Jewish. The attack started after they said yes. Police said they were searching for the assailants.